Direct compounding injection molding device for multi-component recycled plastics based on single screw extruder

Abstract

The application relates to the technical field of injection molding waste recovery, in particular to a multi-component recycled plastic direct mixing injection molding device based on a single-screw extruder. The device comprises a supporting frame, an extruder body, a feeding hopper, a fixed mold and a movable mold, the inside of the fixed mold is provided with a male mold, the inside of the movable mold is provided with a female mold corresponding to the male mold, a chamber capable of accommodating a plastic box is formed between the male mold and the female mold; in the injection molding stage, plastic part stabilizing mechanisms are arranged at the top and the bottom of the fixed mold, the plastic part stabilizing mechanisms are movably connected with the fixed mold, and the plastic part stabilizing mechanisms are used for plugging the overflow raw materials inside and outside the chamber in cooperation with the female mold. The overflow port on the female mold is filled in the injection molding stage by means of the limiting plate, a closed chamber is formed between the male mold and the female mold, the overflow of the molten raw materials is effectively prevented, the forming integrity of the plastic part is ensured, and in the demolding stage, the limiting plate moves downwards to block the box edge part of the plastic box, the plastic box is prevented from being separated from the male mold in advance, and stable positioning is provided for subsequent suction cup grabbing.

Description

Technical Field

[0001] This invention relates to the field of injection molding waste recycling technology, and more specifically, to a multi-component recycled plastic direct mixing injection molding apparatus based on a single-screw extruder. Background Technology

[0002] Injection molding machines, also known as injection molding machines or injection machines, are the main molding equipment used to make various shapes of plastic products from thermoplastic or thermosetting plastics using plastic molds. They are divided into vertical, horizontal, and all-electric types. Injection molding machines heat the plastic and apply high pressure to the molten plastic, causing it to be injected and fill the mold cavity. The working principle of injection molding machines is similar to that of a syringe. It uses the thrust of a screw (or plunger) to inject the plasticized molten state (i.e., viscous flow state) plastic into a closed mold cavity, and obtain the product after solidification and shaping.

[0003] In existing technologies, some plastic boxes are typically shallow (e.g., large jelly boxes). Compared to plastic boxes with greater depth, the shallower plastic boxes have a smaller contact area with the mold during demolding, reducing frictional resistance and making it easier for them to detach from the mold automatically. Moreover, the cross-section of such plastic boxes is mostly conical. When the slope of the box increases, the frictional force between it and the mold decreases sharply, making it easier for the plastic box to detach. Summary of the Invention

[0004] This invention provides a multi-component recycled plastic direct compounding injection molding device based on a single-screw extruder. During the injection stage, a limiting plate fills the overflow port on the die, forming a closed cavity between the punch and die. This effectively prevents molten material from overflowing, ensuring the integrity of the molded part. Furthermore, during the demolding stage, the limiting plate moves downwards to block the edge of the plastic box, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the multi-component recycled plastic direct compounding injection molding device based on a single screw extruder includes a support frame, an extruder body, a feed hopper, a fixed mold and a moving mold. A punch is provided inside the fixed mold, and a die corresponding to the punch is provided inside the moving mold, forming a cavity between the punch and the die that can accommodate a plastic box.

[0006] During the injection molding stage, plastic part stabilizing mechanisms are set at the top and bottom of the fixed mold. The plastic part stabilizing mechanisms are movably connected to the fixed mold. The plastic part stabilizing mechanisms work together with the cavity mold to seal the overflow of material inside and outside the cavity. During the demolding stage, the cavity mold releases the restraint on the plastic part stabilizing mechanisms and moves longitudinally into the cavity with the help of the plastic part stabilizing mechanisms, so as to make the plastic part stabilizing mechanisms and the plastic box misaligned, so as to intercept the plastic box after demolding.

[0007] The plastic part stabilizing mechanism includes a limiting plate that is fitted onto the fixed mold. The limiting plate corresponds to the punch and is located on its top. The cavity corresponding to the limiting plate has an overflow port. During injection molding, the limiting plate, the overflow port, and the inner side of the fixed mold fit together to form a closed cavity between the punch and the cavity.

[0008] In the above technical solution, when the die and the punch are in a certain position... Figure 6 In the state shown, by injecting raw material into the sealed chamber, the raw material fills the sealed chamber, and the limiting plate blocks the overflow port, which restricts the overflow of raw material in the sealed chamber and avoids waste of raw material.

[0009] Furthermore, the plastic part stabilizing mechanism also includes an air vent box that is fixedly connected to the limiting plate and located on the fixed mold. A stabilizing rod that extends into the fixed mold is fixed to the inner wall of the air vent box. The stabilizing rod is used to keep the air vent box moving back and forth in the longitudinal direction.

[0010] In the above technical solution, as the die approaches the punch, the die applies pressure to the limiting plate, which is forced to move upward under the constraint of the stabilizing rod. Conversely, when the die moves away from the punch, a tension spring is elastically fixed between the air vent box and the fixed die. The tension spring is sleeved outside the stabilizing rod. Under the elastic action of the tension spring, the air vent box is pulled back to its original position, causing the limiting plate to move down to the position of the dotted line. In this way, the extended limiting plate intercepts the edge of the plastic box, preventing the plastic box from detaching from the punch.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] By using a limiting plate to fill the overflow port on the cavity mold during the injection molding stage, a closed cavity is formed between the punch and the cavity mold, which effectively prevents the molten material from overflowing and ensures the integrity of the plastic part molding. In addition, during the demolding stage, the limiting plate moves downward to block the edge of the plastic box, preventing the plastic box from detaching from the punch in advance and providing stable positioning for subsequent suction cup gripping. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0014] Figure 2 This is a schematic diagram of the raw material conveying principle of the present invention;

[0015] Figure 3 This is a schematic diagram of the exploded structure of the plastic box and the fixed mold of the present invention;

[0016] Figure 4 This is a schematic diagram of the exploded structure of the concave mold, plastic box, convex mold, and air venting box of the present invention.

[0017] Figure 5 This is a schematic diagram illustrating the cooling airflow principle within the mold of the present invention.

[0018] Figure 6For the present invention Figure 5 Enlarged structural diagram at point A in the diagram;

[0019] Figure 7 This is a schematic diagram of the exploded structure of the air intake box and exhaust box of the present invention;

[0020] Figure 8 This is a schematic diagram of the airflow guidance structure of the exhaust box and the air intake box of the present invention.

[0021] The meanings of the labels in the diagram are as follows:

[0022] 100. Support frame; 101. Extruder body; 102. Feed hopper;

[0023] 110. Fixed mold; 111. Moving mold; 112. Punch; 113. Cavity; 114. Plastic box; 115. Overflow port; 116. Cavity; 117. Air inlet channel; 118. Exhaust channel;

[0024] 120. Plastic part stabilizing mechanism; 121. Limiting plate; 122. Air venting box; 123. Inner plate; 124. Air supply channel; 125. Tension spring; 126. Stabilizing bar;

[0025] 130. Blower; 131. Exhaust box; 132. Exhaust vent;

[0026] 140. Hydraulic rod; 141. Guide plate. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In existing technologies, some plastic boxes are typically shallow (e.g., large jelly boxes). Compared to plastic boxes with greater depth, the shallower plastic boxes have a smaller contact area with the mold during demolding, reducing frictional resistance and making it easier for them to detach from the mold automatically. Moreover, the cross-section of such plastic boxes is mostly conical. When the slope of the box increases, the frictional force between it and the mold decreases sharply, making it easier for the plastic box to detach.

[0029] Therefore, in view of the above problems, the present invention provides a multi-component recycled plastic direct compounding injection molding apparatus based on a single-screw extruder, see [link to relevant documentation]. Figures 1-4As shown, the extruder includes a support frame 100, an extruder body 101, a feed hopper 102, a fixed mold 110, and a moving mold 111. A punch 112 is located inside the fixed mold 110, and a die 113 corresponding to the punch 112 is located inside the moving mold 111. During injection molding, the moving mold 111 moves closer to the fixed mold 110 under the drive of a hydraulic device until the die 113 fits against the fixed mold 110. At this point, a cavity is formed between the punch 112 and the die 113 to accommodate a plastic box 114. Then, recycled plastic is added to the extruder body 101 through the feed hopper 102 for mixing and melting (the molten plastic is hereinafter referred to as raw material). The screw inside the extruder body 101 provides power to the raw material, which flows from the injection hole in the fixed mold 110 into the cavity between the punch 112 and the die 113. (The reference is missing from the original text.) Figure 5 As indicated by the middle arrow, after injection molding is completed and cooling is achieved, a molded plastic box 114 is formed inside the cavity.

[0030] During the injection molding stage, plastic part stabilizing mechanisms 120 are provided at both the top and bottom of the fixed mold 110. The plastic part stabilizing mechanisms 120 are movably connected to the fixed mold 110. The plastic part stabilizing mechanisms 120, together with the cavity mold 113, are used to seal the overflow of material inside and outside the cavity. Next, during the demolding stage, the cavity mold 113 releases the restraint on the plastic part stabilizing mechanism 120, and with the help of the plastic part stabilizing mechanism 120, it makes a longitudinal displacement into the cavity and penetrates into the cavity, so that the plastic part stabilizing mechanism 120 and the plastic box 114 are misaligned, so as to intercept the demolded plastic box 114 and prevent the plastic box 114 from directly detaching from the punch 112. Please refer to the following text for details:

[0031] First, the specific structure of the plastic part stabilizing mechanism 120 is disclosed. The plastic part stabilizing mechanism 120 includes a limiting plate 121 that is fitted onto the fixed mold 110. The limiting plate 121 corresponds to the punch 112 and is located on its top. The cavity mold 113 corresponding to the limiting plate 121 has an overflow port 115. During injection molding, the limiting plate 121, the overflow port 115, and the inner side of the fixed mold 110 are fitted together, so that a closed cavity is formed between the punch 112 and the cavity mold 113. Therefore, when the cavity mold 113 and the punch 112 are in a closed position, the plastic part stabilizing mechanism 120 can be stabilized. Figure 6 In the indicated state, by injecting raw material into the sealed chamber, the raw material fills the sealed chamber, and the limiting plate 121 blocks the overflow port 115, limiting the overflow of raw material in the sealed chamber and avoiding waste caused by the overflow of raw material.

[0032] Secondly, after injection molding, the unformed plastic box 114 inside the cavity is cooled to solidify and form. During this process, a cavity 116 is formed in the punch 112. The cavity 116 is connected to an air inlet channel 117 and an exhaust channel 118 in the fixed mold 110. The air inlet channel 117 is connected to an external blower 130. When cooling, the blower 130 blows cold air into the cavity 116. The end of the exhaust channel 118 away from the cavity 116 is connected to the external environment. Thus, when cooling the unformed plastic box 114, the blower 130 draws in cold air through the air inlet channel 117 into the cavity 116. The drawing in of cold air cools the inner wall of the cavity 116, and the heated cold air is discharged from the exhaust channel 118. This achieves the cooling of the inner wall of the plastic box 114 and accelerates its solidification speed.

[0033] It should be noted that the above only uses air cooling to cool the plastic box 114. In order to improve the cooling effect, air cooling and water cooling can also be combined, but this will not be elaborated on here.

[0034] In addition, combined Figure 7 and Figure 8 As shown, an exhaust box 131 is fixedly installed on the fixed mold 110 at the junction of the exhaust channel 118 and the external environment. The exhaust box 131 is hollow inside. During the cooling stage, the airflow discharged from the exhaust channel 118 is transported to the exhaust box 131. Since the exhaust box 131 has an exhaust port 132 that is horizontally oriented towards the inside of the fixed mold 110, the exhaust port 132 is used to transport the airflow discharged from the exhaust channel 118 to the inside of the fixed mold 110. Therefore, the airflow discharged through the exhaust channel 118 is guided by the exhaust box 131 and discharged from the exhaust port 132. That is, the airflow blows towards the inside of the fixed mold 110 in a horizontal state.

[0035] Return to Figure 4 , Figure 5 As shown, during the demolding stage, the concave mold 113 moves away from the convex mold 112, and the solidified plastic box 114 is freed from the restriction of the concave mold 113 and easily slides off the convex mold 112.

[0036] To solve the above problems, based on Figure 4 Based on this, and then combined Figure 7 , Figure 8As shown, the plastic part stabilizing mechanism 120 also includes an air vent box 122 fixedly connected to the limiting plate 121 and located on the fixed mold 110. A stabilizing rod 126, extending into the fixed mold 110, is fixed to the inner wall of the air vent box 122. The stabilizing rod 126 is used to maintain the longitudinal reciprocating movement of the air vent box 122. The reason for the reciprocating movement of the air vent box 122 is that: during the process of the die 113 approaching the punch 112, the die 113 applies pressure to the limiting plate 121, forcing the limiting plate 121 to move upward under the constraint of the stabilizing rod 126. Conversely, when the die 113 moves away from the punch 112, a tension spring 125 is elastically fixedly connected between the air vent box 122 and the fixed mold 110. The tension spring 125 is sleeved outside the stabilizing rod 126. Under the elastic action of the tension spring 125, the air vent box 122 is pulled back to its original position, causing the limiting plate 121 to move downward to the position indicated by the dotted line (reference). Figure 6 As shown), in this way, the extended limiting plate 121 intercepts the edge of the plastic box 114, preventing the plastic box 114 from detaching from the punch 112.

[0037] In other words, by using the limiting plate 121 to fill the overflow port 115 on the cavity mold 113 during the injection molding stage, a closed cavity is formed between the punch 112 and the cavity mold 113, which effectively prevents the molten material from overflowing and ensures the integrity of the plastic part molding. Furthermore, during the demolding stage, the limiting plate 121 moves downward to block the edge of the plastic box 114, preventing the plastic box 114 from detaching from the punch 112 in advance, and providing stable positioning for subsequent gripping by the suction cup (not shown in the figure).

[0038] When the suction cup grips the plastic box 114, a hydraulic rod 140 is fixedly installed on the fixed mold 110. The telescopic end of the hydraulic rod 140 passes through the exhaust box 131, and a guide plate 141 is fixed to the end. The guide plate 141 has an inclined surface, and the air duct box 122 near the inclined surface is open on one side. Thus, when the suction cup grips the plastic box 114, the telescopic end of the hydraulic rod 140 pushes the guide plate 141 to move towards the open side of the air duct box 122. The inclined surface of the guide plate 141 forces the air duct box 122 to overcome the elastic potential energy of the tension spring 125 and move upward, so that the limiting plate 121 releases the restriction on the plastic box 114. Then, the suction cup transfers the plastic box 114, improving production efficiency.

[0039] Secondly, due to the limitations of the internal cooling pipe design of the fixed mold 110 and the moving mold 111, the cooling is mainly applied to the body of the plastic box 114. As the thickness of the plastic box 114 increases, the cooling time required for the plastic box 114 increases, thereby increasing energy consumption. To address this, an inclined inner plate 123 is fixedly connected to the inside of the air intake box 122. An air supply channel 124 for airflow is formed between the inner plate 123 and the air intake box 122. The air supply channel 124 has an inlet end and an outlet end, with the outlet end pointing towards the body of the plastic box 114. On the other hand, the inlet end is horizontally lower than the exhaust port 132 to smoothly introduce airflow into the air supply channel 124. The purpose is that by making the inlet end horizontally lower than the exhaust port 132, more air can be introduced into the air supply channel 124 when airflow is delivered from the exhaust port 132 to the inlet end, resulting in a better cooling effect on the plastic box 114.

[0040] Specific working principle: When the die 113 just detaches from the plastic box 114, the airflow discharged from the exhaust channel 118 continues to flow. At this time, the airflow is discharged from the exhaust box 131, enters the air supply channel 124 through the air inlet, and finally exits from the exhaust end. The airflow blows towards the back of the plastic box 114, achieving the purpose of cooling the back of the plastic box 114. At the same time, the cool air works together to dissipate heat from the inner wall of the plastic box 114, achieving dual heat dissipation from the inside and outside of the plastic box 114, thus improving the heat dissipation effect.

[0041] After cooling is complete, the blower 130 stops working, and the plastic box 114 is transferred. Each molded plastic box 114 has a small amount of residual waste. The waste is cleaned manually, collected and utilized to improve the recycling rate of waste.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-component recycled plastic direct mixing and injection molding device based on a single-screw extruder, characterized in that: It includes a support frame (100), an extruder body (101), a feed hopper (102), a fixed die (110) and a moving die (111). A punch (112) is provided inside the fixed die (110), and a die (113) corresponding to the punch (112) is provided inside the moving die (111). A cavity capable of accommodating a plastic box (114) is formed between the punch (112) and the die (113). During the injection molding stage, plastic part stabilizing mechanisms (120) are provided at the top and bottom of the fixed mold (110). The plastic part stabilizing mechanism (120) is movably connected to the fixed mold (110). The plastic part stabilizing mechanism (120) works with the cavity mold (113) to seal the overflow of raw materials inside and outside the cavity. During the demolding stage, the cavity mold (113) releases the restraint on the plastic part stabilizing mechanism (120) and moves longitudinally into the cavity with the help of the plastic part stabilizing mechanism (120) and penetrates into the cavity, so that the plastic part stabilizing mechanism (120) and the plastic box (114) are misaligned, so as to intercept the demolded plastic box (114). The plastic part stabilizing mechanism (120) includes a limiting plate (121) fitted on the fixed mold (110). The limiting plate (121) corresponds to the punch (112) and is located on its top. The cavity (113) corresponding to the limiting plate (121) has an overflow port (115). During injection molding, the limiting plate (121), the overflow port (115), and the inner side of the fixed mold (110) are fitted together, so that the punch (112) and the cavity (113) form a closed cavity.

2. The multi-component recycled plastic direct compounding injection molding device based on a single-screw extruder according to claim 1, characterized in that: A cavity (116) is formed in the punch (112). The cavity (116) is connected to an air inlet channel (117) and an exhaust channel (118) in the fixed mold (110). The air inlet channel (117) is connected to an external blower (130). When the blower (130) is cooling, it blows cold air into the cavity (116). The end of the exhaust channel (118) away from the cavity (116) is connected to the external environment.

3. The multi-component recycled plastic direct compounding injection molding device based on a single-screw extruder according to claim 2, characterized in that: An exhaust box (131) is fixedly installed on the fixed mold (110) at the junction of the exhaust channel (118) and the external environment. The exhaust box (131) is hollow inside and has an exhaust port (132) that is horizontally facing the inside of the fixed mold (110). The exhaust port (132) is used to transport the airflow discharged from the exhaust channel (118) to the inside of the fixed mold (110).

4. The multi-component recycled plastic direct compounding injection molding device based on a single-screw extruder according to claim 3, characterized in that: The plastic part stabilizing mechanism (120) also includes an air duct box (122) fixedly connected to the limiting plate (121) and located on the fixed mold (110). The inner wall of the air duct box (122) is fixed with a stabilizing rod (126) that extends into the fixed mold (110). The stabilizing rod (126) is used to keep the air duct box (122) moving longitudinally back and forth.

5. The multi-component recycled plastic direct compounding injection molding device based on a single-screw extruder according to claim 4, characterized in that: A tension spring (125) is elastically fixed between the air venting box (122) and the fixed mold (110), and the tension spring (125) is sleeved on the outside of the stabilizer bar (126).

6. The multi-component recycled plastic direct compounding injection molding device based on a single-screw extruder according to claim 5, characterized in that: A hydraulic rod (140) is fixedly installed on the fixed mold (110). The telescopic end of the hydraulic rod (140) is inserted into the exhaust box (131), and a guide plate (141) is fixed at the end.

7. The multi-component recycled plastic direct compounding injection molding device based on a single-screw extruder according to claim 6, characterized in that: The guide plate (141) has an inclined surface, and the air box (122) near the inclined surface is open on one side.

8. The multi-component recycled plastic direct compounding injection molding device based on a single-screw extruder according to claim 7, characterized in that: An inclined inner plate (123) is fixedly connected to the inside of the air duct box (122). An air supply channel (124) for airflow is formed between the inner plate (123) and the air duct box (122). The air supply channel (124) has an air inlet end and an air outlet end, with the air outlet end pointing towards the body of the plastic box (114).

9. The multi-component recycled plastic direct compounding injection molding device based on a single-screw extruder according to claim 8, characterized in that: The air inlet is positioned horizontally below the exhaust port (132) to facilitate the introduction of airflow into the air delivery channel (124).

Images